The New Zealand Government funds one cochlear implant per child, but research had shown that children do a lot better with two, so the Earls had launched a fundraising campaign to get second implants for their children. The implants cost $50,000 each.

Sometimes they forget that the children can't hear as well as everyone else, Mr Earl said.

"It's when they get into a social environment with other kids or in the car with the windows open and wind comes in, situations like that they struggle to hear."

And what they hear is a manufactured sound made by electrodes.

"They don't hear through the ear like we do, but through the device."

Mum Nicola Earl said with two implants the sound would not necessarily be louder.

"One (implant) is almost a flat sound. If they have two we're told it's a more full or rich sound, surround sound, coming from both sides."

When Benji and Sadie are not wearing their implants, such as in the shower or at the pool, they can't hear a thing, she said.

The couple had given themselves two years to raise the $100,000 they needed.

Their campaign, cheers4ears, kicked off last month with a quiz night at the Good Home in New Plymouth.

They had set up both a Facebook page and one on the givealittle website. And if anyone bought blinds from Blindz Direct and mentioned cheers4ears the company would donate 10 per cent of the sale.

In April they had a Crossfit WoDothan planned at Crossfit New Plymouth, in Fitzroy.

A Wod is the workout of the day and people were getting sponsored to do as many as they could in a certain time period. Some "crazy people" such as Mr Earl were planning to work out for the whole 24 hours.

If a business donated $250 it could have its name on T-shirts or on the sponsors board, he said.

There was also an auction evening planned for later in the year.

Lobby group 2ears2hear spokesman, Sym Gardiner, said to get the full benefit of a second implant children needed to get it early.

So the Earls couldn't wait around for the government to catch up with every other Western government and fund two implants, he said.

A child with one implant needed educational support that costs about $30,000 a year or about $400,000 over the child's entire time at school.